Besides, it was pretty clear to me reading the sequence of events at Fukushima that there was entirely too little thought given to backup decoupling - there was too much of a zipper effect of one failure leading to another.
I'm not a lay person on this - I worked for 3 years on airliner designs, and much of that is finding ways to deal with failure cases. The nuke industry could learn a lot by consulting with airframe engineers.
Yes, that would work, as long as you also protected the switchgear and the power cabling leading to the pumps that serve the reactor.
The nuke industry could learn a lot by consulting with airframe engineers.
I think the nuke industry in general does pay attention to these things; I was actually somewhat surprised to find that the designers of Fukushima had missed such an obvious failure mode.
1. hydrogen being vented into an enclosed area
2. no backup method for determining coolant levels
3. backup generators were not protected
4. no backup method for adding coolant (I would have had a gravity fed backup system)
5. critical systems were located too close to the reactor - I would have moved them further away so they could be repaired without the workers being irradiated
None of these are expensive to do.
3. Backup generators were located in different areas. The only mistake is that they were ALL at ground level. That's unfortunate that they were all wiped out at the same time but one of the largest Tsunami ever, some stuff that almost never happens. They'll learn from that.
> None of these are expensive to do.
Yeah, when you are building the plant, it's not expensive to do. When you have to modify an existing design, it's way more expensive and you'll have to make a good case for why you need it.
The key idea is nobody has managed to design parts that won't fail. But they have figured out how to design highly reliable systems out of parts that fail.
Current designs use lots of redundant safety systems. New designs depend more on simple physics...eg., fuel that expands enough when it heats to damp down the reaction, or large quantities of coolant with very high thermal capacity and conductivity. At Argonne's IFR project, they shut down coolant circulation and electric power, and the reactor quietly shut down with no damage.
The ultimate solution is probably the molten salt reactor. With liquid fuel you continually remove fission products, and with most of those gone you don't have decay heat issues anymore.
But why would you even take that risk? Not to mention that tsunamis can easily reach 100 feet in wave height; I'm not sure you could build a seawall that could keep one out.